What is graphitization degree?

The degree of graphitization is an essential measure used to assess how close carbon atoms are to forming a tightly-packed hexagonal graphite crystal structure. In an ideal scenario, the graphite crystal structure appears as a closely-packed hexagonal arrangement with lattice constants of a=0.2461 nm and c=0.6708 nm. However, in natural graphite crystals, there are numerous defects, and the degree of graphitization of synthetic graphite, which is used in practical applications, is greatly influenced by manufacturing processes and raw materials. Generally, the closer the lattice dimensions are to the ideal graphite lattice constants, the higher the degree of graphitization. X-ray diffraction (XRD) is commonly used to measure this degree by determining the interlayer spacing d002 of the graphite (002) plane and then calculating it using the Mering-Maire formula (also known as the Franklin formula). The graphitization degree is an indicator of the structural orderliness and properties, such as electrical conductivity, of carbon materials.

Importance of Graphitization Degree

The degree of graphitization is a critical parameter for various high-performance carbon materials. For example, graphite materials are essential for achieving a specific graphitization degree in carbon/carbon (C/C) composites used in aerospace brake applications and anode materials for lithium-ion batteries. In these applications, a high graphitization degree directly impacts the material's mechanical strength, thermal stability, and electrical conductivity. Therefore, testing the graphitization degree is crucial for quality control and serves as a basis for adjusting manufacturing process parameters.

Factors Affecting Graphitization

The degree of graphitization in synthetic graphite is influenced by several factors, including the type of precursor materials, heat treatment temperature, and duration. Generally, higher heat treatment temperatures and longer durations promote a higher degree of graphitization by facilitating the rearrangement of carbon atoms into the ideal hexagonal structure. Additionally, the choice of precursor materials, such as petroleum coke or pitch-based precursors, can impact the ease with which graphitization occurs. High-purity precursors tend to result in a more ordered graphite structure.

Applications Requiring High Graphitization Degree

Aerospace Brake Systems: Carbon/carbon composites used in aerospace brake systems require a high degree of graphitization to ensure excellent thermal stability and mechanical strength. The high-temperature environments encountered during braking demand materials that can maintain their structural integrity and performance under stress.

Lithium-Ion Batteries: The anode materials for lithium-ion batteries necessitate a high graphitization degree to achieve superior electrical conductivity and lithium-ion intercalation efficiency. This contributes to the battery's overall performance, including its charge/discharge rate and cycle life.

Nuclear Reactors: Graphite materials used in nuclear reactors as moderators and reflectors must possess a high graphitization degree to ensure high thermal conductivity and structural stability under radiation exposure.

Electronic Devices: Graphite's excellent electrical conductivity makes it a preferred material for various electronic applications, such as electrodes in electrochemical sensors and conductive fillers in polymer composites.

In conclusion, the graphitization degree is a critical parameter for assessing the structural orderliness and performance of carbon materials. Its significance spans various high-performance applications, including aerospace, energy storage, and electronics. Accurate measurement and control of graphitization degree are essential for ensuring the quality and performance of graphite materials. As research continues to advance, the development of more efficient and sustainable graphitization processes will further enhance the applicability and performance of these versatile materials.

Semicorex offers high graphitization degree graphite material for semiconductor industry If you have any inquiries or need additional details, please don't hesitate to get in touch with us.

Contact phone # +86-13567891907

Email: sales@semicorex.com